Phenolic antioxidants have been used for many years to stabilize organic material against oxidative degradation. For example, 4,4'-methylenebis-(2,6-di-tert-butylphenol) is a commercial antioxidant. Other phenolic antioxidants containing methylene bridges are described in U.S. Pat. No. 3,026,264, U.S. Pat. No. 3,211,652 and U.S. Pat. No. 3,297,575.